In December 2013, an experiment was done to determine whether a 48-year-old Ironman athlete could perform the Ironman tests on a raw vegan diet. The subject had been a raw fruits and vegetables vegan for six years before starting the study.
The Ironman trials consist of rigorous triathlon sports, including swimming, bicycling, and running. The subject finished the Ironman triathlon in 41 hours and 18 minutes. His performance was compared to 10 other Ironman athletes in the same age bracket who were on mixed diets. Although the vegan subject in this study was able to take in more respiratory oxygen than the mixed-diet athletes were able to take in, it was unclear whether a vegan triathlon athlete can perform better than mixed-diet athletes can perform.
It is thought that a vegan diet may be better than a mixed diet for long-distance endurance trials due to the enhanced oxygen intake that the vegan competitor had taken in. Further study needs to be done concerning whether a vegan diet is definitely better than a conventional diet for long-distance endurance events; however, it was determined that a vegan diet for long-distance endurance does no harm to the participant.